Fresno (1700/sq. km) also has less than half the population density of Nantes or Nice (4200-4800/sq. km). It's not exactly a fair comparison if the area of the city is far larger unless the last-kilometer transit seamlessly scales to last-2km transit. You can actually walk to a reasonable number of places, or take a bus 1-2 km to many more, from a main station in Nantes, Nice, or any number of similarly-sized cities in many countries.
Don't think either Nantes or Nice have dedicated TGV lines.
A better example in France would be Bordeaux.
Not really, the high-speed line was supposed to connect to Spain and Toulouse and the beaches of courses (it's not named LGV SEA for nothing).
Fresno is a county seat and there's Cal State. That's it.
Same in France, every local baron wanted his dedicated HS line, so now we got plenty but only one is profitable.
Do you still think that qualifies as "empty spaces"?